英文關鍵字
background
bacteria
black
bottles
canal
chamber
channel
chemical
city
concrete
crises
dirty
ditch
drain
drainage
dump
dumping
earth
environment
garbage
green
ground
gutter
inorganic
landfill
management
nature
open
outskirts
overflow
plant
plastic
pollution
potable
rainwater
river
rubbish
sewage
sewer
stream
system
tip
toxic
tunnel
untreated
urban
virus
waste
water